1. Field of the Invention
The present invention relates to a motor control apparatus used in, e.g., office automation (OA) equipment such as a printer for a personal computer, a wordprocessor, or the like.
2. Related Background Art
For example, in a motor which can be driven as a brushless DC motor a Hall element is used for detecting a position of a magnetic pole of a rotor for performing energization control, and an optical or magnetic encoder is used for detecting a rotational speed of the rotor.
However, such a brushless motor poses the following problems.
(1Position alignment between a stator magnetic pole and a Hall element is required. PA1 (2) When energization switching is performed by the Hall element, since the positions of the Hall element and the stator are uniquely determined, the energization method of a motor is defined accordingly. For example, the electrical angular position of the Hall element is different with respect to the stator by 45.degree.. Therefore, in order to perform two ways of energization control in one motor, the number of Hall elements is doubled, and the Hall elements must be arranged at positions suitable for energization control.
Note that Japanese Patent Laid-Open (Kokai) Nos. 62-193548 and 62-193549 disclose motors that can be driven as stepping motors for performing energization control using encoder outputs. These patents disclose only motor structures in which encoders are provided at predetermined positions, and there is no disclosure about a drive control circuit, method, and the like of the motor.